Adhesives have been used in many structural applications. Such structural applications have included vehicles, computer cases, buildings, and appliances. For example, structural adhesives have been used in vehicle assembly (e.g., automobile and aircraft assembly) to replace or augment conventional joining techniques such as welds, nuts and bolts, and rivets. Epoxy compositions are known and have been used for structural adhesive applications. Tougheners have been included in epoxy adhesive compositions to improve the impact resistance of the adhesive. See, for example, U.S. Pat. No. 6,800,157 (Tarbutton et al.).
Aluminum flake has been incorporated as a filler into coatings and adhesives. See, for example, U.S. Pat. No. 4,920,002 (Cussot et al.). Certain fatty acids are sometimes used during the milling of aluminum flake as milling aids. See, for example, U.S. Pat. No. 3,234,038 (Stephens et al.) and U.S. Pat. No. 3,181,962 (Rolles) and European Pat. Pub. No. 0015725, published Sep. 17, 1980.